Spherical lenses are used to reduce the size of the Waterproof Case lens. When shooting images underwater, straight objects may look distorted or shooting images may appear less clear than those of normal shooting due to the different optical refraction of water. This is not a malfunction.
By using the replacement door pack for diving accessory AKA-RD1 (sold separately) in the SPK-AS1 waterproof case, it is possible to prevent image blur and distortion. You can also use the underwater housing MPK-AS3.
By using the Dive Door (AKA-DDX1) accessory (sold separately) in the waterproof case (SPK-X1), it is possible to prevent images from being distorted or blurred.